Balanced solenoid valve

Abstract

A valve assembly includes a solenoid can having an internal coil. A valve body connected to the solenoid can includes an inlet port and a first valve seat. An axially adjustable retainer threadably connected to the valve body includes an end portion defining a second valve seat. A homogenous valve member/armature slidably disposed in the valve body moves in the presence of a coil generated magnetic flux between valve closed and valve open positions. A valve member/armature first surface area is in fluid communication with a pressurized fluid through the inlet port. A valve member/armature second surface area is in fluid communication with the pressurized fluid in the valve closed position. The first surface area is equal to the second surface area and the pressurized fluid acts equally on the first and second surface areas defining a pressure balanced condition in the valve closed position.

1. A solenoid operated valve assembly, comprising:
 a solenoid can; 
 a valve body connected to the solenoid can; 
 a pole piece connected to the solenoid can operating to transfer a magnetic flux; 
 a homogenous valve member/armature slidably disposed in the valve body and movable from a valve closed position to a valve open position in the presence of the magnetic flux; 
 a bushing portion of the valve body engaged with the solenoid can having a predetermined length establishing a non-zero clearance gap between the pole piece and the valve member/armature in either an energized or a de-energized position of the valve member/armature; and 
 a solenoid bushing retained in the solenoid can by the bushing portion, the solenoid bushing having a bushing sleeve, the valve member/armature received in and in sliding contact with the bushing sleeve; 
 a coil received in the solenoid can adapted when energized to provide the magnetic flux to the pole piece to move the valve member/armature from the de-energized position toward the pole piece to the energized position; and 
 a valve element having a first side adapted to contact the bushing portion in the energized position of the valve member/armature. 
 
     
     
       2. The solenoid operated valve assembly of  claim 1 , wherein the valve element is a resilient material allowing compression of the valve element and over-shoot of the valve member/armature when the valve element contacts the bushing portion, wherein the clearance gap allows for the over-shoot without permitting contact between the valve member/armature and the pole piece. 
     
     
       3. The solenoid operated valve assembly of  claim 1 , wherein the pole piece includes a plurality of threads adapted to be threadably received in the solenoid can to permit the pole piece to be axially adjustable, wherein axial adjustment of the pole piece is operable to at least increase the clearance gap above a minimum value between the pole piece and the valve member/armature in either the energized or the de-energized position of the valve member/armature. 
     
     
       4. The solenoid operated valve assembly of  claim 1 , wherein the bushing portion includes a seat surface created proximate to a free end. 
     
     
       5. The solenoid operated valve assembly of  claim 1 , wherein the solenoid bushing includes a bushing sleeve adapted to slidably receive the valve member/armature, wherein the bushing portion is adapted to retain the solenoid bushing. 
     
     
       6. The solenoid operated valve assembly of  claim 1 , wherein the position of the pole piece with respect to the valve member/armature defines a clearance gap having a non-zero value for all operating conditions of the valve assembly. 
     
     
       7. A solenoid operated valve assembly, comprising:
 a solenoid can; 
 a valve body connected to the solenoid can having a valve seat; 
 a pole piece threadably connected to the solenoid can operable to transfer a magnetic flux; 
 a valve member/armature slidably disposed in the valve body and movable from a valve closed position to a valve open position in the presence of the magnetic flux, the valve member/armature having a resilient material valve element; 
 a solenoid bushing in direct contact with the solenoid can and slidably receiving the valve member/armature; 
 a bushing portion in direct contact with the solenoid bushing, the bushing portion having a predetermined length creating a non-zero width clearance gap between the pole piece and the valve member/armature in either an energized or a de-energized position of the valve member/armature to prevent contact between the valve member/armature and the pole piece; and 
 a biasing member positioned in the valve body between and in direct contact with the solenoid bushing and the valve member/armature, the biasing member continuously biasing the valve member/armature away from the pole piece and toward the valve closed position wherein the valve element is in contact with the valve seat. 
 
     
     
       8. The solenoid operated valve assembly of  claim 7 , wherein the valve member/armature includes a first pressure equalizing passage extending throughout an entire length of the valve member/armature. 
     
     
       9. The solenoid operated valve assembly of  claim 8 , further comprising a second pressure equalizing passage extending throughout the pole piece and axially aligned with the first pressure equalizing passage. 
     
     
       10. The solenoid operated valve assembly of  claim 7 , wherein the valve element of the valve member/armature comprises an over-molded elastomer. 
     
     
       11. The solenoid operated valve assembly of  claim 7 , wherein the pole piece includes a plurality of threads adapted to be threadably received in the solenoid can to permit the pole piece to be axially adjustable with respect to the valve member/armature, wherein axial adjustment of the pole piece is operable to at least increase the clearance gap between the pole piece and the valve member/armature in either the energized or the de-energized position of the valve member/armature. 
     
     
       12. The solenoid operated valve assembly of  claim 11 , wherein axial adjustment of the pole piece is operable to move the pole piece closer to the valve member/armature to initially set the clearance gap at a minimum value between the pole piece and the valve member/armature defined in the energized position of the valve member/armature. 
     
     
       13. A solenoid operated valve assembly, comprising:
 a solenoid can having a coil; 
 a valve body connected to the solenoid can; 
 a pole piece connected to the solenoid can operable to transfer a magnetic flux; 
 a valve member/armature created as a unitary combination of a valve member connected to an armature, the valve member/armature slidably disposed in the valve body and movable from a valve closed position to a valve open position in the presence of the magnetic flux; and 
 a solenoid bushing received in the solenoid can having a length creating a non-zero clearance gap between the pole piece and the valve member/armature in either an energized or a de-energized position of the valve member/armature, a first end of the valve member/armature being slidably disposed within a bushing sleeve of the solenoid bushing; and 
 a biasing member in contact with both the solenoid bushing and the valve member/armature normally biasing the valve member/armature to the de-energized position when the coil is de-energized. 
 
     
     
       14. The solenoid operated valve assembly of  claim 13 , wherein the valve member/armature is made from a magnetically effected material. 
     
     
       15. The solenoid operated valve assembly of  claim 13 , wherein the valve member/armature comprises an elastomeric valve element over-molded onto the valve member.